A Heron, in White

Way back in August of last year, on my Friday off, I came in as a volunteer and joined the Park’s seasonal Biological Technician (Hi Mark!) to hit the river and work on an ongoing crayfish survey. We put the boat in at the new Chilton Creek access, planning to work our way upstream to Logyard. Almost immediately, we spotted a white heron/egret upstream and across the river.

I started shooting photos and Mark tried to get closer, but the bird was wary and wouldn’t allow us to get very close (the photos below are fairly deep crops from 24 MP originals.) We saw the bird several times throughout the day, but never managed to get closer than that first encounter. It was too small to be a Great Egret and too large to be a Cattle Egret, so I called it a Snowy Egret (subject to later revision) and we moved on.

Then I get home, download the photos and see this:

Ok, that’s obviously NOT a Snowy Egret. The bill is too short and stout and the legs are greenish-yellow, not black. It looks more like a very small, white Great Blue Heron than anything else I can think of, but that can’t be right either. The only other possibility that occurred to me at this point was a Little Blue Heron, though they’re fairly rare here on the river. But do they have a white phase? I didn’t know, so I headed to the Cornell Laboratory of Ornithology’s Little Blue Heron page. And there it is. Juvenile Little Blue Herons are white, except for dark tips on the outer primaries.

This photo clearly shows dark tips to the last few primaries in the right wing, so we now have a confirmed juvenile Little Blue Heron. The next question, with this being a juvenile, was could he have been fledged locally?

Little Blues sometimes nest near other colonial species and there are Great Blue rookeries within a couple of miles in both directions from where we first encountered this bird. One of those I’ve visited nearly every year since I first located it in the late ‘80s and I’m reasonably sure that there have been no Little Blues nesting in the area.

A check of the Missouri Breeding Bird Atlas shows that the only breeding blocks rated “Possible” are located in the southeast Lowlands with a single outlier “Probable” in northeastern Shannon County. That Shannon County block was also the only “Probable” for the entire state.

Range Map Courtesy of the Cornell Laboratory of Ornithology

Plus, according to Cornell’s range map, Little Blues breed mainly along the Gulf coast, but disperse well to the north following the breeding season, before migrating south to their wintering areas in Central and South America. And that’s likely what this individual was – a post-breeding dispersal from the Gulf, who has undoubtedly long since headed south for the winter.